hirudin and Ischemia

Recommendations for transitioning from therapy with heparin or a low-molecular-weight heparin preparation to therapy with an oral anticoagulant in patients with acute venous or arterial thromboembolism have undergone several changes during the last two decades. Physicians are now comfortable with beginning treatment with an oral anticoagulant once the diagnosis is confirmed, and loading doses are no longer considered to be necessary. Exceptions to early transition may be necessary in patients with an extensive iliofemoral or axillary-subclavian vein thrombosis or pulmonary embolism where thrombolytic agents may be indicated, or in individuals who require surgery or other invasive procedures, or if there are concerns about bleeding. The avoidance of early transition to oral anticoagulants in patients with acute heparin-induced thrombocytopenia also has been advised because of the potential for further thrombotic complications, including venous limb gangrene and warfarin-induced skin necrosis.

Topics: Administration, Oral; Anticoagulants; Arginine; Blood Coagulation; Blood Coagulation Factors; Chondroitin Sulfates; Dermatan Sulfate; Drug Combinations; Gangrene; Heparin; Heparitin Sulfate; Hirudins; Humans; Ischemia; Leg; Necrosis; Pipecolic Acids; Recombinant Proteins; Skin; Sulfonamides; Thrombocytopenia; Thrombosis; Warfarin

The therapeutic use of leeches in medicine dates back to 50 b.c. and was cited by ancient authors. The medicinal leech, Hirudo medicinalis, has been used with increasing frequency during the past few years by reconstructive surgeons to help salvage ischaemic tissues. We aim to summarise the anatomy, physiology, and pharmacological mechanisms of action of leeches to provide reconstructive surgeons with a theoretical basis for their use.

Topics: Animals; Hirudin Therapy; Hirudins; Hirudo medicinalis; Humans; Ischemia; Surgical Flaps

Topics: Anticoagulants; Aortic Valve Insufficiency; Arginine; Autoantibodies; Autoimmune Diseases; Female; Fingers; Heart Valve Prosthesis Implantation; Heparin; Hirudins; Humans; Ischemia; Middle Aged; Necrosis; Pipecolic Acids; Platelet Activation; Platelet Factor 4; Postoperative Complications; Raynaud Disease; Recombinant Proteins; Sulfonamides; Thrombocytopenia; Thrombosis; Toes; Warfarin

Chronic kidney disease is associated with an increased risk of ischemic and bleeding events after percutaneous coronary intervention (PCI). The direct thrombin inhibitor bivalirudin reduces these combined events. We sought to assess whether this benefit was influenced by renal function. A meta-analysis of 3 randomized trials (n = 5,035) comparing bivalirudin with heparin during PCI, stratified by estimated creatinine clearance using the Cockcroft-Gault equation (>90 [n = 1,578], 90 to 60 [n = 2,163], 59 to 30 [n = 1,255], and <30 ml/min [n = 39]), was conducted. The composite end points of death, myocardial infarction or revascularization, hemorrhage, and combined ischemic or bleeding events were assessed. A common odds ratio for each creatinine clearance strata was estimated with a random-effects model. The interaction between renal impairment and benefit from bivalirudin was assessed. Adverse ischemic and bleeding events increased with decreasing renal function. The relative benefit of bivalirudin with respect to ischemic and bleeding events was maintained within each stratum. The absolute benefit in terms of ischemic and bleeding complications increased with decreasing creatinine clearance (normal 2.2%, mild 5.8%, moderate 7.7%, severe 14.4%; p trend <0.001, interaction p = 0.044). Renal dysfunction remains a prevalent risk factor for ischemic and bleeding events in patients who undergo PCI. Bivalirudin provides greater absolute benefit in patients with impaired renal function.

Topics: Adult; Age Factors; Aged; Aged, 80 and over; Angioplasty, Balloon, Coronary; Coronary Artery Disease; Creatinine; Female; Fibrinolytic Agents; Hirudins; Humans; Hypertension; Ischemia; Kidney Failure, Chronic; Male; Middle Aged; Peptide Fragments; Postoperative Hemorrhage; Randomized Controlled Trials as Topic; Recombinant Proteins; Risk Factors; Sex Factors

We assessed the incidence, predictors, and outcomes of gastrointestinal bleeding (GIB) in patients with acute coronary syndromes (ACS).. GIB is a potential hemorrhagic complication in patients with ACS treated with antithrombotic and/or antiplatelet medications. The clinical outcomes associated with GIB in this setting have not been systematically studied.. In the ACUITY (Acute Catheterization and Urgent Intervention Triage Strategy) trial, 13,819 patients with moderate- and high-risk ACS, enrolled at 450 centers in 17 countries between August 2003 and December 2005, were randomized to the open-label use of 1 of 3 antithrombin regimens (heparin plus a glycoprotein IIb/IIIa inhibitor, bivalirudin plus a glycoprotein IIb/IIIa inhibitor, or bivalirudin monotherapy).. GIB within 30 days occurred in 178 patients (1.3%). Older age, baseline anemia, longer duration of study drug administration before angiogram, smoking, ST-segment deviation>or=1 mm, and diabetes were identified as independent predictors of GIB. On multivariable analysis, GIB was strongly associated with 30-day all-cause mortality (hazard ratio [HR]: 4.87 [interquartile range (IQR) 2.61 to 9.08], p<0.0001), cardiac mortality (HR: 5.35 [IQR 2.71 to 10.59], p<0.0001), and composite ischemia (HR: 1.94 [IQR 1.14 to 3.30], p=0.014), as well as with 1-year all-cause mortality (HR: 3.97 [IQR 2.64 to 5.99], p<0.0001), cardiac mortality (HR: 3.77 [IQR 2.14 to 6.63], p<0.0001), myocardial infarction (HR: 1.74 [IQR 1.01 to 3.02], p=0.047), and composite ischemia (HR: 1.90 [IQR 1.37 to 2.64], p=0.0001). Patients who experienced GIB had significantly higher rates of stent thrombosis compared with patients without GIB (5.8% vs. 2.4%, p=0.009).. GIB is a serious condition in the scenario of ACS and is independently associated with mortality and ischemic complications.

Topics: Acute Coronary Syndrome; Age Factors; Aged; Angioplasty, Balloon, Coronary; Anticoagulants; Clopidogrel; Coronary Artery Bypass; Female; Gastrointestinal Hemorrhage; Heparin; Hirudins; Humans; Incidence; Ischemia; Length of Stay; Male; Middle Aged; Multivariate Analysis; Myocardial Infarction; Peptide Fragments; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Recombinant Proteins; Risk Assessment; Sex Factors; Stents; Thrombosis; Ticlopidine

Among patients who undergo percutaneous coronary intervention, renal impairment is associated with an excessive risk of bleeding and ischemic events. Bivalirudin provides comparable suppression of ischemic events with a decrease in bleeding events compared with heparin and glycoprotein IIb/IIIa inhibition. We examined the relation between adverse events, renal impairment, and antithrombotic therapy within a randomized comparison. The Second Randomized Evaluation in PCI Linking Bivalirudin to Reduced Clinical Events per-protocol study population was assessed. Renal function was defined as calculated creatinine clearance <60 ml/min. Events within the overall study population and within each study arm were assessed. Thirty-day events by renal function were compared by chi-square test and logistic regression. Late mortality was compared by log-rank test. Interaction analyses were performed. Among 5,710 patients, renal impairment was associated with increased ischemic events (hazard ratio 1.45, 95% confidence interval 1.13 to 1.88, p = 0.004), bleeding complications (hazard ratio 1.72, 95% confidence interval 1.06 to 2.80, p = 0.028), and excessive 12-month mortality (hazard ratio 3.85, 95% confidence interval 2.67 to 5.54, p <0.001). Bivalirudin provided suppression of ischemic events that was comparable to heparin and glycoprotein IIb/IIIa inhibition regardless of renal impairment. Fewer bleeding events with bivalirudin were also evident irrespective of renal dysfunction. No interaction between treatment assignment, bleeding or ischemic complications, and renal impairment was observed. The safety and efficacy of bivalirudin compared with heparin and planned glycoprotein IIb/IIIa inhibition in this high-risk group are comparable and consistent with the results of the overall trial.

Topics: Abciximab; Aged; Angioplasty, Balloon, Coronary; Antibodies, Monoclonal; Anticoagulants; Atherectomy, Coronary; Chi-Square Distribution; Double-Blind Method; Drug Therapy, Combination; Eptifibatide; Female; Fibrinolytic Agents; Hemorrhage; Heparin; Hirudins; Humans; Immunoglobulin Fab Fragments; Intraoperative Complications; Ischemia; Logistic Models; Male; Middle Aged; Peptide Fragments; Peptides; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Recombinant Proteins; Renal Insufficiency; Stents; Survival Analysis; Treatment Outcome

Predictors of complications in peripheral percutaneous interventions (PPI) with bivalirudin as a base anticoagulant have not yet been defined. The Angiomax Peripheral Procedure Registry of Vascular Events (APPROVE) offers a unique opportunity to analyze predictors of complications with bivalirudin in PPI.. APPROVE was a prospective, open-label, multi-center clinical trial that assessed the feasibility of bivalirudin in renal, iliac and femoral interventions. Bivalirudin was administered intravenously at a dose of 0.75 mg per kg bolus followed by an infusion of 1.75 mg per kg per hour for the duration of the procedure. Glycoprotein (GP) IIb-IIIa inhibitors were permitted at the discretion of the treating physician. Multiple independent variables were included in a Logistic Regression model to determine predictors of the combined endpoints of ischemic (death, amputation, unplanned urgent revascularization at the treated site, myocardial infarction) and major bleeding or major bleeding alone, assessed during hospitalization and at 30 days.. Predictors of in-hospital ischemic and major bleed events were congestive heart failure (p = 0.0173) and exchanges to larger sheath size (ELS) (p = 0.0045). The strongest predictor of major bleeding alone at discharge (p = 0.0041) and at 30 days (p = 0.0016) was the number of ELS. Also, female gender (p = 0.08) and low weight (stratified by gender with < 80 kg versus > 92 kg for males and < 62 kg versus > 77 kg for females) (p = 0.096) showed a trend toward predicting major bleeding at 30 days. Of 505 patients in APPROVE, 26 patients required more than one sheath exchange. Of these, 24 were ELS. Despite this small number, these patients accounted for most of the major bleeding events that occurred (11.5% versus 1.7% in-hospital bleeding for the patients with ELS versus single sheath use respectively, and 15.4% versus 3.1% for 30-day bleeding). GP IIb-IIIa inhibitors (n = 22) use and thrombotic lesions (3%) were not predictors of ischemic and/or bleeding complications.. ELS during PPI is a strong predictor of bleeding events when bivalirudin is used as a base anticoagulant. Female gender and low weight also tend to contribute to major bleeding.

Topics: Aged; Anticoagulants; Catheterization, Peripheral; Feasibility Studies; Female; Femoral Artery; Hemorrhage; Hirudins; Hospitalization; Humans; Iliac Artery; Ischemia; Male; Peptide Fragments; Prospective Studies; Recombinant Proteins; Registries; Renal Artery; Risk Factors; Time Factors; Treatment Outcome

The direct thrombin inhibitor bivalirudin has been associated with better efficacy and less bleeding than heparin during coronary balloon angioplasty but has not been widely tested during contemporary percutaneous coronary intervention (PCI).. To determine the efficacy of bivalirudin, with glycoprotein IIb/IIIa (Gp IIb/IIIa) inhibition on a provisional basis for complications during PCI, compared with heparin plus planned Gp IIb/IIIa blockade with regard to protection from periprocedural ischemic and hemorrhagic complications.. The Randomized Evaluation in PCI Linking Angiomax to Reduced Clinical Events (REPLACE)-2 trial, a randomized, double-blind, active-controlled trial conducted among 6010 patients undergoing urgent or elective PCI at 233 community or referral hospitals in 9 countries from October 2001 through August 2002.. Patients were randomly assigned to receive intravenous bivalirudin (0.75-mg/kg bolus plus 1.75 mg/kg per hour for the duration of PCI), with provisional Gp IIb/IIIa inhibition (n = 2999), or heparin (65-U/kg bolus) with planned Gp IIb/IIIa inhibition (abciximab or eptifibatide) (n = 3011). Both groups received daily aspirin and a thienopyridine for at least 30 days after PCI.. The primary composite end point was 30-day incidence of death, myocardial infarction, urgent repeat revascularization, or in-hospital major bleeding; the secondary composite end point was 30-day incidence of death, myocardial infarction, or urgent repeat revascularization.. Provisional Gp IIb/IIIa blockade was administered to 7.2% of patients in the bivalirudin group. By 30 days, the primary composite end point had occurred among 9.2% of patients in the bivalirudin group vs 10.0% of patients in the heparin-plus-Gp IIb/IIIa group (odds ratio, 0.92; 95% confidence interval, 0.77-1.09; P =.32). The secondary composite end point occurred in 7.6% of patients in the bivalirudin vs 7.1% of patients in the heparin-plus-Gp IIb/IIIa groups (odds ratio, 1.09; 95% confidence interval 0.90-1.32; P =.40). Prespecified statistical criteria for noninferiority to heparin plus Gp IIb/IIIa were satisfied for both end points. In-hospital major bleeding rates were significantly reduced by bivalirudin (2.4% vs 4.1%; P<.001).. Bivalirudin with provisional Gp IIb/IIIa blockade is statistically not inferior to heparin plus planned Gp IIb/IIIa blockade during contemporary PCI with regard to suppression of acute ischemic end points and is associated with less bleeding.

Topics: Abciximab; Aged; Angioplasty, Balloon, Coronary; Antibodies, Monoclonal; Anticoagulants; Atherectomy, Coronary; Double-Blind Method; Drug Therapy, Combination; Eptifibatide; Female; Fibrinolytic Agents; Hemorrhage; Heparin; Hirudins; Humans; Immunoglobulin Fab Fragments; Intraoperative Complications; Ischemia; Male; Middle Aged; Peptide Fragments; Peptides; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Recombinant Proteins; Stents; Survival Analysis; Treatment Outcome

Heparin is often administered during and after coronary angioplasty to prevent closure of the dilated vessel. However, ischemic or hemorrhagic complications occur in 5 to 10 percent of treated patients. We studied whether these complications could be prevented when the direct thrombin inhibitor bivalirudin (Hirulog) was used in place of heparin.. We performed a double-blind, randomized trial in 4098 patients undergoing angioplasty for unstable or postinfarction angina. Patients were assigned to receive either heparin or bivalirudin immediately before angioplasty. The primary end point were death in the hospital, myocardial infarction, abrupt vessel closure, or rapid clinical deterioration of cardiac origin.. In the total study group, bivalirudin did not significantly reduce the incidence of the primary end point (11.4 percent, vs. 12.2 percent for heparin) but did result in a lower incidence of bleeding (3.8 percent vs. 9.8 percent, P < 0.001). In the prospectively stratified subgroup of 704 patients with postinfarction angina, bivalirudin therapy resulted in a lower incidence of the primary end point (9.1 percent vs. 14.2 percent, P = 0.04) and a lower incidence of bleeding (3.0 percent vs. 11.1 percent, P < 0.001), but in a similar cumulative rate of death, myocardial infarction, and repeated revascularization in the six months after angioplasty (20.5 percent vs. 25.1 percent, P = 0.17).. Bivalirudin was at least as effective as high-dose heparin in preventing ischemic complications in patients who underwent angioplasty for unstable angina, and it carried a lower risk of bleeding. Bivalirudin, as compared with heparin, reduced the risk of immediate ischemic complications in patients with postinfarction angina, but this difference was no longer apparent after six months.

Topics: Aged; Angina Pectoris; Angina, Unstable; Angioplasty, Balloon, Coronary; Double-Blind Method; Female; Hemorrhage; Heparin; Hirudin Therapy; Hirudins; Humans; Ischemia; Male; Middle Aged; Myocardial Infarction; Peptide Fragments; Postoperative Complications; Recombinant Proteins; Serine Proteinase Inhibitors

Coagulation factor V (FV) is distributed in plasma and platelet pools, which are distinguished by physical and functional differences. FV has been extensively studied for its roles in coagulation. The roles of FV in other physiologic pathways remain understudied.. Hind limb ischemia was produced in transgenic mice by femoral artery ligation, with different levels of FV gene expression restricted to the plasma or platelets.. Hind limb blood flow perfusion in mice with higher platelet FV was significantly increased. The expression of major angiogenesis-related factors was correlated with the level of FV during ischemia. Furthermore, a platelet depletion and transfusion procedure showed that the transfusion of platelets with higher levels of FV into transgenic mice with undetectable platelet FV significantly rescued the ischemia-mediated impairments in blood flow perfusion. Immunohistochemistry analysis also indicated markedly increased capillary formation in the ischemic muscle of mice with higher platelet FV. Moreover, thrombin activity was significantly higher in the mice with higher platelet FV. Platelets expressing higher levels of FV stimulated increased endothelial cell migration. Hind limb blood flow perfusion was significantly blocked by thrombin inhibitor.. These findings suggest that platelet-derived FV contributes to the control of angiogenesis and is likely associated with thrombin generation.

Topics: Angiogenic Proteins; Animals; Antithrombins; Blood Flow Velocity; Blood Platelets; Cell Movement; Cells, Cultured; Disease Models, Animal; Endothelial Cells; Factor V; Genotype; Hindlimb; Hirudins; Ischemia; Mice, Inbred C57BL; Mice, Transgenic; Muscle, Skeletal; Neovascularization, Physiologic; Phenotype; Platelet Endothelial Cell Adhesion Molecule-1; Platelet Transfusion; Regional Blood Flow; Thrombin; Time Factors

The effects of antithrombotic drugs on random and free flap survival have been investigated in the past, but the experimental and clinical results are not in agreement. A perforator-based critical ischaemia model was used to evaluate the effects of different perioperatively administered pharmaceutical agents on tissue ischaemia and to assess the potential additional haemorheological or vasodilative effects of antithrombotics on flap microcirculation. Combined laser Doppler flowmetry and remission spectroscopy revealed an increase in certain microcirculation parameters in most groups in comparison with saline controls, and these changes correlated with flap survival. Clopidogrel and hirudin significantly improved the amount of viable flap tissue in comparison with controls, while unfractioned heparin had a negative effect on flap survival. Low molecular weight heparin, aspirin, pentoxifylline, and hydroxyethyl starch had no impact on the amount of viable flap tissue. A higher complication rate was observed in all experimental groups, but only clopidogrel had a negative impact on the flap viability. Our results add to the body of evidence supporting the conclusion that perioperative antithrombotic treatment improves flap survival. Clopidogrel and hirudin are effective pharmacological agents that significantly increased the viability of perforator-based skin flaps in rats, but at a higher risk of postoperative bleeding.

Topics: Animals; Aspirin; Clopidogrel; Disease Models, Animal; Fibrinolytic Agents; Graft Survival; Heparin; Hirudins; Ischemia; Laser-Doppler Flowmetry; Male; Microcirculation; Pentoxifylline; Postoperative Complications; Rats; Rats, Wistar; Skin Diseases; Skin Transplantation; Surgical Flaps; Ticlopidine

Anticoagulation therapy during percutaneous coronary intervention (PCI) has been the focus of numerous clinical trials. Low-anticoagulant doses have been successfully used in patients undergoing elective PCI, a situation with low-thrombogenic milieu.. The purpose of the study was to evaluate the safety and efficacy of shorter duration of treatment with bivalirudin in patients undergoing elective PCI and receiving optimal antiplatelet therapy.. We compared patients undergoing PCI who received aspirin and clopidogrel loading dose in addition to either conventional bivalirudin dosing (intravenous [IV] bolus of 0.75 + 1.75 mg/kg per h for the duration of PCI; n = 197) or a reduced bivalirudin dose (IV bolus of 0.75 mg/kg; n = 200).. Procedural success was obtained in 100% of cases. The primary end point (in-hospital death, acute myocardial infarction, or need for urgent target vessel revascularization) did not differ between both the groups (6 patients [3%] in the conventional dose group vs 5 patients [2.5%] in the reduced dose group). Major bleeding occurred in 1 patient in the conventional dose group (P = nonsignificant [NS]). Minor bleeding occurred in 4 patients (2%) in the conventional dose group vs 5 patients (2.5%) in the reduced dose group (P = NS) and was mainly due to bleeding at entry site.. In patients undergoing elective PCI, using bivalirudin as a bolus only dosing may be as effective and less costly when compared with bolus followed by an infusion for the duration of the intervention. A larger study is needed to confirm our findings.

Topics: Aged; Alabama; Antithrombins; Aspirin; Clopidogrel; Dose-Response Relationship, Drug; Elective Surgical Procedures; Female; Hemorrhage; Hirudins; Humans; Incidence; Infusions, Intravenous; Injections, Intravenous; Ischemia; Male; Middle Aged; Peptide Fragments; Percutaneous Coronary Intervention; Platelet Aggregation Inhibitors; Recombinant Proteins; Retrospective Studies; Severity of Illness Index; Thrombosis; Ticlopidine

Topics: Angioplasty; Anticoagulants; Constriction, Pathologic; Hemorrhage; Heparin; Hirudins; Humans; Ischemia; Peptide Fragments; Peripheral Vascular Diseases; Radiography; Recombinant Proteins; Risk Assessment; Risk Factors; Severity of Illness Index; Treatment Outcome

To present real-world data to evaluate the safety and effectiveness of bivalirudin, a direct thrombin inhibitor, in an unselected group of patients undergoing percutaneous peripheral interventions (PPI).. Data were extracted from a prospectively collected peripheral vascular registry developed for quality assurance measures at 2 centers. Of 398 consecutive patients (195 men; mean age 69.4+/-11.3 years) who underwent PPI in a 2-year period, 369 (92.7%) received bivalirudin (0.75 mg/kg bolus followed by a 1.75 mg/kg/h infusion) and 29 (7.3%) received unfractionated heparin (UFH). In the bivalirudin sample, critical limb ischemia was present in 28.0% of patients, TASC D lesion in 29.5%, and angiographic thrombus in 7.8% of vessels. Demographic, clinical, procedural, and angiographic variables and in-hospital complications were analyzed. All in-hospital adverse events were independently adjudicated.. Procedural success (<30% residual narrowing) was achieved in 359 (97.3%) patients receiving bivalirudin. Adverse events included stroke (1, 0.3%), acute renal failure (1, 0.3%), major bleeding (3, 0.8%), distal embolization (11, 3.0%), vascular access complications (2, 0.5%), and minor amputation (2, 0.5%).. Bivalirudin had an excellent safety profile in a real-life cohort of patients undergoing PPI, including high-risk patients with critical limb ischemia and TASC D lesions. In-hospital major bleeding and other adverse events were infrequent. A randomized trial of bivalirudin versus UFH is needed to verify these results and establish bivalirudin as a standard anticoagulant in PPI.

Topics: Aged; Aged, 80 and over; Angioplasty; Anticoagulants; Chi-Square Distribution; Constriction, Pathologic; Female; Hemorrhage; Heparin; Hirudins; Humans; Inpatients; Iowa; Ischemia; Logistic Models; Male; Middle Aged; Peptide Fragments; Peripheral Vascular Diseases; Radiography; Recombinant Proteins; Registries; Retrospective Studies; Risk Assessment; Risk Factors; Severity of Illness Index; Treatment Outcome

Topics: Adult; Amputation, Surgical; Anticoagulants; Extremities; Female; Hirudins; Humans; Ischemia; Male; Middle Aged; Peripheral Vascular Diseases; Recombinant Proteins; Thrombin; Thrombophilia

Thrombin plays a role in cerebral ischemia as rats subjected to focal cerebral ischemia were protected by the intracerebral injection of hirudin, a selective thrombin inhibitor. To separate the roles of thrombin in cell death and in coagulation, we have used an in vitro approach to test the effect of hirudin and of protease nexin-1 (PN-1), a cerebral thrombin inhibitor, on neuronal ischemia. Rat organotypic hippocampal slice cultures were subjected to oxygen (5%) and glucose (1 mmol/L) deprivation (OGD) during 30 min. Hirudin or PN-1 administered after OGD significantly prevented neuronal death in the CA1 region. After 24 h, there was a marked increase in thrombin immunoreactivity on Western blots. Thrombin therefore contributes to ischemic damage in neural tissue in vitro.

Topics: Animals; Animals, Newborn; Blotting, Western; Cell Death; Disease Models, Animal; Dose-Response Relationship, Drug; Gene Expression Regulation; Glucose; Hippocampus; Hirudin Therapy; Hirudins; Hypoxia; In Vitro Techniques; Ischemia; Neurons; Protease Inhibitors; Rats; Rats, Sprague-Dawley; Thrombin

The objective of this retrospective chart review was to evaluate the safety and feasibility of using the direct thrombin inhibitor bivalirudin as the procedural anticoagulant in patients undergoing percutaneous peripheral intervention (PPI).. Patients with peripheral artery disease are in general a high-risk population that requires safe and reliable anticoagulation with complete thrombin inhibition. Bivalirudin, a direct thrombin inhibitor, has been shown to be as effective as heparin, but with fewer bleeding events in PCI trials, and recent data suggest that bivalirudin may provide the same benefits in PPI.. This was a retrospective chart review of patients who underwent PPI with bivalirudin as the foundation anticoagulant. Bivalirudin was administered as a 0.75 mg per kg bolus, followed by a 1.75 mg per kg per hour infusion for the duration of the procedure. The primary endpoint was procedural success defined as residual stenosis less than or equal to 20%. Ischemic and hemorrhagic events were collected, as well as time-to-sheath removal, ambulation and discharge.. Data were collected for 150 patients. Procedural success was achieved in 98.5%. Ischemic events were low: death (2.0%), myocardial infarction (0.0%), urgent revascularization (0.8%). Major and minor hemorrhage occurred in 4.7% and 2.0% of patients, respectively. Time-to-sheath removal, ambulation and discharge were short.. Bivalirudin provided effective anticoagulation in these generally high-risk patients undergoing PPI. Ischemic and bleeding events were low and comparable to those reported in the literature, suggesting that bivalirudin is safe to use in this population.

Topics: Aged; Angioplasty; Anticoagulants; Antithrombins; Arterial Occlusive Diseases; Feasibility Studies; Female; Hemorrhage; Hirudins; Humans; Incidence; Ischemia; Male; Medical Records; Middle Aged; Peptide Fragments; Platelet Glycoprotein GPIIb-IIIa Complex; Recombinant Proteins; Retrospective Studies; Treatment Outcome; Urokinase-Type Plasminogen Activator

Emerging findings have demonstrated the critical role of blood clotting factors in the formation and stabilization of embryonic blood vessels. Whether a similar role is true during post-natal angiogenesis remains to be determined. Here we sought to determine whether the suppression of thrombin generation with anticoagulant drugs at doses routinely used for therapeutic purposes would affect the angiogenesis pattern following hindlimb ischemia in rats. Animals were treated with r-hirudin or enoxaparin within six hours post induction of hindlimb ischemia, whereas two other groups received oral anticoagulation warfarin beginning at day 3 post-ischemia or saline (as control). The revascularization anatomical and functional responses were evaluated 30 days following tissue ischemia. Chronic administration of the drugs resulted in stable anticoagulation in all animals throughout the experiment. Animals that received drugs with fast anticoagulation effects (i.e. r-hirudin and enoxaparin) presented a significant decrease in capillary density and capillary-to-myocyte ratio compared to control animals. These effects were not associated with changes in relative perfusion of the hindlimb at steady state. These anti-angiogenic effects occur in a time-dependent manner, since delayed inhibition of coagulation (>72 hours) presents no adverse effect on the angiogenic response. We conclude that the use of anticoagulant drugs immediately after tissue ischemia induction hampers in vivo angiogenic response in a rodent hindlimb ischemia model.

Topics: Animals; Anticoagulants; Blood Coagulation Factors; Disease Models, Animal; Enoxaparin; Hindlimb; Hirudins; Ischemia; Kinetics; Neovascularization, Physiologic; Rats; Rats, Inbred Lew; Time Factors; Warfarin

This study modeled the comparative costs and effectiveness of anticoagulation with bivalirudin alone, heparin alone, and heparin combined with a glycoprotein IIb/IIIa-receptor inhibitor (GPI) in patients undergoing percutaneous coronary intervention (PCI) in Sweden.. GPIs are prescribed for -40% to 50% of patients undergoing PCI in Sweden. However, because treatment practices vary between hospitals, the model analyzed a cohort in which different proportions of patients (0%-100%) would receive a GPI in addition to heparin and the remaining patients would receive heparin monotherapy. This mixed cohort was compared with a cohort treated with bivalirudin. Abciximab was used as the GPI comparator, as this is the only GPI currently approved in Sweden for patients undergoing PCI. Pooled data from 3 studies (REPLACE-2 [second Randomized Evaluation of PCI Linking Angiomax to Reduced Clinical Events], ESPRIT [European/Australasian Stroke Prevention in Reversible Ischaemia Trial], and EPISTENT [Evaluation of Platelet IIb/IIIa Inhibitor for Stenting]) were used as the source for the probabilities of myocardial infarction (MI), urgent revascularization (UR), major and minor bleeding (Thrombolysis in Myocardial Infarction study definitions), and death. Treatment costs associated with these complications were obtained from 4 Swedish hospitals, and official drug prices were obtained from the Swedish Pharmacopoeia. All costs were presented in 2006 Swedish kronor (SEK). The model was evaluated over a 30-day time frame from the perspective of a Swedish hospital. The modeled patient population was 63 years old, weighed 78 kg, and was 75% male.. Compared with a pattern in which heparin plus a GPI was used in 50% of all PCIs and heparin alone was used in the remaining 50%, bivalirudin treatment was associated with a significant reduction in all complications in the model (P < 0.05), including a mean of 18.2 fewer MIs, 1.6 fewer URs, 15.3 fewer bleeding events, and 1.3 fewer deaths per 1000 treated patients. Bivalirudin therapy also was associated with a significant reduction in total drug and health care costs per patient (SEK -1301; 95% Cl, -1367 to -1229). The benefit of bivalirudin was sensitive to the rate of GPI use: additional reductions in rates of MI, UR, and death were seen at lower rates of GPI use, and additional reductions in rates of bleeding and costs of drugs and health care utilization were seen at higher rates of GPI use.. In this model, anticoagulation with bivalirudin in patients undergoing PCI was cost-effective compared with heparin alone and heparin plus a GPI. In a hypothetical Swedish hospital unit using equal proportions of heparin alone and heparin plus a GPI, a switch to bivalirudin would reduce the risk of both ischemic events and bleeding events, resulting in savings in total drug and health care costs.

Topics: Angioplasty, Balloon, Coronary; Cost-Benefit Analysis; Decision Making; Female; Hemorrhage; Heparin; Hirudins; Humans; Ischemia; Male; Middle Aged; Models, Theoretical; Peptide Fragments; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Prospective Studies; Randomized Controlled Trials as Topic; Recombinant Proteins; Sweden

The combination of glycoprotein (GP) IIb-IIIa inhibition and direct thrombin inhibition (DTI) with bivalirudin (Angiomax, The Medicines Company, Cambridge, Massachusetts) have shown ischemic and hemorrhagic outcomes benefit in coronary interventions and may have similar benefits in percutaneous peripheral interventions (PPI). The high incidence of diabetes, chronic renal disease, platelet dysfunction, hypercoagulability, inflammation and a thrombus-rich environment make a GP IIb-IIIa and DTI combination with tirofiban (Aggrastat Merck and Company, Inc., Whitehouse Station, New Jersey) an attractive anticoagulation strategy in the PPI treatment of critical limb ischemia (CLI).. Between May 1, 2001 and January 31, 2003, a CLI treatment group of 149 patients received PPI with bivalirudin (0.75 mg per kg bolus with 1.75 mg per kg per hour periprocedural infusion) and tirofiban (10 mcg per kg per minute bolus with 12-hour 0.1 mcg per kg per minute infusion) as an anticoagulation and antiplatelet strategy, and were compared to a matched unfractionated heparin (UFH) control group without GP IIb-IIIa inhibitors. Clinical and hemostasis outcomes were analyzed, including distal embolization (DE).. Procedural success was 95.9% and 97.3% in the UFH control group and DTI-GP IIb-IIIa group, respectively. Significant differences were observed in the sheath removal time < 2 hours (60.5% UFH group versus 19.4% DTI-GP IIb-IIIa group; p = < 0.0001). Vascular closure devices were used equally in both groups. No statistical significance was observed in major and minor complications, femoral access complications, acute (< 48 hours) or subacute (30 days) vessel thrombosis, and 6-month duplex ultrasound restenosis rate between the DTI-GP IIb-IIIa versus the UFH group. A trend towards statistical significance was observed in the 6-month secondary re-intervention and limb salvage rates (10.7% versus 18.8%; p = 0.0501 and 93.9% versus 88.5%; p = 0.053) in the DTI-GP IIb-IIIa versus the UFH group, respectively. Angiographically relevant DE occurred in 4 of 149 (1.3%) and 8 of 149 (5.4%) of the bivalirudin-tirofiban and UFH groups, respectively.. The combination of DTI with bivalirudin and GP IIb-IIIa inhibition with tirofiban is a safe and feasible alternative anticoagulation and antiplatelet strategy in PPI, and may offer improved clinical and hemostasis outcomes in treating CLI. A larger, prospective randomized trial is warranted.

Topics: Acute Disease; Aged; Angioplasty, Balloon; Anticoagulants; Feasibility Studies; Female; Follow-Up Studies; Hirudins; Humans; Ischemia; Leg; Male; Myocardial Ischemia; Peptide Fragments; Peripheral Vascular Diseases; Platelet Aggregation Inhibitors; Platelet Glycoprotein GPIIb-IIIa Complex; Recombinant Proteins; Retrospective Studies; Thrombin; Tirofiban; Treatment Outcome; Tyrosine

Heparin-induced thrombocytopenia with thrombosis (HITT) is a rare complication of cardiac surgery with cardiopulmonary bypass. We report two cases of HITT treated with the direct thrombin inhibitor Lepirudin. Immediate diagnosis was essential to prompt heparin discontinuation and successful early Lepirudin administration in the first case. In the second, the presence of an intra-aortic balloon pump delayed HITT recognition, and Lepirudin infusion could not prevent limb amputation. In both cases HITT occurred earlier (< 5 days after heparin exposure) than its usual presentation.

Topics: Adult; Aged; Amputation, Surgical; Anticoagulants; Aorta; Aortic Aneurysm; Aortic Dissection; Aortic Valve; Blood Vessel Prosthesis Implantation; Combined Modality Therapy; Coronary Artery Bypass; Early Diagnosis; Fibrinolytic Agents; Heart Valve Prosthesis Implantation; Heparin; Hirudins; Humans; Intra-Aortic Balloon Pumping; Ischemia; Leg; Male; Marfan Syndrome; Mitral Valve; Postoperative Complications; Recombinant Proteins; Thrombocytopenia; Thrombophlebitis

Evidence shows that leukocyte recruitment into inflamed liver sinusoids does not require selectins, with one notable exception: ischemia-reperfusion (I/R). We used intravital microscopy to directly visualize the liver microcirculation during I/R and localized endotoxemia (liver superfused with lipopolysaccharide). General anti-selectin therapy (fucoidan) or anti-adhesion therapy with an antithrombin inhibitor (hirudin) was also used. Many neutrophils rolled and adhered in postsinusoidal vessels and sequestered in the sinusoids during I/R and local endotoxin superfusion. Although fucoidan blocked rolling in both forms of inflammation, leukocyte recruitment into sinusoids was only blocked in I/R. Adhesion was also inhibited in postischemic sinusoids with a second anti-adhesive agent (hirudin). Because liver I/R inevitably induces ischemia upstream in the intestine, anti-selectin therapy may prevent intestinal injury, which could prevent downstream liver inflammation. To test this hypothesis, we completely removed the intestine and rerouted blood flow from the superior mesenteric artery to the superior mesenteric vein. I/R was induced in the liver microcirculation, and many leukocytes rolled and adhered in postsinusoidal venules and adhered in sinusoids. Although fucoidan significantly reduced the rolling in postsinusoidal vessels, adhesion persisted in the sinusoids. Our data suggest that anti-adhesion therapy is effective in liver I/R in the sinusoids and postsinusoidal venules, perhaps in part due to its beneficial effect on the intestine.

Topics: Animals; Cats; Cell Adhesion; Endotoxemia; Fibrinolytic Agents; Hirudins; Ischemia; Leukocyte Count; Leukocytes; Liver Circulation; Microcirculation; Polysaccharides; Reperfusion Injury; Selectins

A 60-year-old woman was admitted because of acute ischemia of the right leg. The patient had been immobilized during diagnostic procedures for a thoracic paraspinal space-occupying lesion and over 5 days had received unfractionated sodium heparin by subcutaneous injection. The pedal pulses were no longer palpable.. The thrombocyte count had fallen from 207,000/microliter to 45,000/microliter. Angiography revealed occlusion of the common femoral artery. Heparin-induced platelet aggregation (HIPA) test demonstrated type II heparin-induced thrombocytopenia. Thrombectomy was performed and intraoperatively an i.v. bolus of the recombinant hirudin, lepirudin (Refludan), was given (0.2 mg/kg body weight), continual lepirudin infusion being continued postoperatively. Normal blood flow was re-established in the limb and the pedal pulse was palpable. There were no complications.. Recombinant hirudin is the only alternative licensed in Germany to heparin and seem to be suitable also for the intraoperative bolus administration in heparin-induced thromboembolic vascular occlusions.

Topics: Angiography, Digital Subtraction; Anticoagulants; Arterial Occlusive Diseases; Female; Femoral Artery; Heparin; Hirudin Therapy; Hirudins; Humans; Infusions, Intravenous; Injections, Intravenous; Intraoperative Care; Ischemia; Leg; Middle Aged; Platelet Aggregation; Platelet Count; Postoperative Care; Recombinant Proteins; Thrombectomy; Thrombocytopenia